This work is related to two main topics: the study of the carbohydrate of the blood-clotting and other circulatory glycoproteins and determination of how the vitamin K-dependent amino acid, gamma-carboxyglutamic acid, functions in blood coagulation. The studies on the carbohydrate currently involve a) determination of the distribution and function of alpha-galactoside residues in prothrombins and other blood-clotting components and b) the biosynthesis of various derivatives of sialic acid and the functions of these derivatives in vivo. The vitamin K-dependent amino acid, gamma-carboxyglutamic acid, functions in calcium and membrane-binding for prothrombin, factor X, factor IX, and factor VII. The properties of these protein-membrane interactions are being pursued to eventually determine the precise structures at the protein-membrane interface and thereby determine the unique functional properties of gamma-carboxyglutamic acid. In addition to understanding one type of protein-membrane interaction, these studies should assist in our understanding of the complex kinetics resulting from the interaction of proteins, membrane and calcium ions during the blood-clotting reactions.